In the prior art, fluid coupling arrangements have been provided for transmitting the rotational energy of an automotive vehicle's engine output shaft to the input shaft of the vehicle's automatic power transmission. Typical of these arrangements have been the torque convertors. All of these arrangements have presented definite problems with respect to power loss, fuel waste, and general inefficiency in energy conversion and power transmission.
Without some slippage in the connection between the vehicle's power source and power transmission, at low engine speed and vehicle speed, engine torque would be insufficient to overcome the load imposed by the inertia of the vehicle and its contents. Thus, the engine would be unable to move the vehicle from a standstill or to stop the vehicle, either in forward or reverse gear, smoothly and without stalling.
Slippage is always present in a fluid coupling, to some degree. This is because there is no direct mechanical linkage between the engine's output shaft and the transmission's input shaft. This everpresent slippage results in a loss of power, the degree of which may vary with the engine speed, vehicle load and other factors. Coincident with this power loss is a waste of fuel. Due to the increasing scarcity and rising cost of petroleum products this fuel waste is a critical factor to be considered.